1. Field of the Invention
This invention relates to wearable devices that dispense chemicals such as insect repellents and/or fragrances.
2. Description of the Related Art
Various techniques have been developed to provide humans with protection from insect bites. For insect control inside buildings a primary emphasis is placed on trying to keep insects from entering the building at all (e.g. placing screens over windows). This sometimes is supplemented with chemical treatment of room air and/or the use of traps. See e.g. U.S. Pat. Nos. 6,582,714 and 7,175,815, and also U.S. Patent Application Publications 2005/0079113, 2006/0039835, 2006/0137241, and 2007/0036688.
When the individual is outdoors where the area cannot be effectively screened, and the individual is mostly staying in a particular area (e.g. at a picnic, or on a patio near a building), traps and repellents are the primary focus.
Alternatively, when the individual is moving away from a single area that they control, individuals often apply a personal insect repellent to clothing or directly to their skin. However, some consumers have expressed a reluctance to apply insect repellents directly to their skin or to delicate clothing.
As a result, portable electrical devices having a fan and an insecticide source have been developed. These devices may have a clip so that they can easily be mounted on a belt, a purse, or even a pocket, and thus be “worn” by the consumer as they move outside. The device may draw air through, or blow air past, a substrate impregnated with an insect repellent or other air treatment chemical, thereby dispensing the active into the air, preferably (in the case of a repellent) downward along the outside of a human's clothing. See U.S. Pat. Nos. 6,296,902, 7,007,861, 7,152,809, and 7,168,630, and U.S. Patent Application Publication Nos. 2003/0175171, 2003/0175171, 2007/0183940, 2009/0008411, and 2009/0060799.
However, some such devices may blow the active too far out away from the human body, causing too little of the active to reach locations of primary concern (e.g. near ankles). Other such devices do not provide a way of minimizing waste of the active, such as while blower operation is suspended between uses. Still other such devices are unduly costly, are too heavy or have other deficiencies.
There have even been a variety of attempts to develop use indicators associated with air treatment devices, so that consumers can tell when the device needs servicing/refilling. See U.S. Pat. Nos. 4,062,649, 4,293,095, 4,824,827, 5,293,648, and U.S. Patent Application Publication No. 2008/0141928, which is incorporated herein by reference.
However, in some such devices the amount of air moving past the substrate does not correspond to the amount of air that flows past the useful life indicator. This could possibly cause the useful life indicator to indicate that the device is still effective after the insect repellent has been depleted.
Hence, a need exists for improved devices for dispensing insect control actives and other air treatment chemicals, particularly those that can operate without applying chemicals directly to the skin or clothing and more accurately display the useful life of the device.
In view of the advances in the art provided by the devices of U.S. Patent Application Publication Nos. 2008/0141928 and 2009/0008411 even further improvements to this technology would be beneficial to consumers.